Which is the correct form of equilibrium expression of the following reaction.
2PbS(s)+3O2(g)reverse arrow 2PbOs + 2SO2g
Why is the answer
Kc= SO2 power 2/O2 power 3
Why in particular is this the arrangement for equilibrium expression?
Thank you
The equilibrium expression is a mathematical representation of the equilibrium constant for a given reaction. It shows the relationship between the concentrations of the reactants and products at equilibrium. To determine the correct form of the equilibrium expression, we follow a few steps:
1. Write the balanced chemical equation for the reaction:
2PbS(s) + 3O2(g) ⇌ 2PbO(s) + 2SO2(g)
2. Identify the coefficients of the reactants and products in the balanced equation. These coefficients indicate the stoichiometry of the reaction. In this case, the coefficients are 2, 3, 2, and 2, respectively.
3. Now, write the equilibrium expression using the concentrations of the species involved. The general form of the equilibrium expression is:
Kc = ([C]^c × [D]^d) / ([A]^a × [B]^b)
Here:
A and B represent the reactants (PbS and O2),
C and D represent the products (PbO and SO2),
a, b, c, and d represent the stoichiometric coefficients of the reactants and products respectively.
4. Apply the stoichiometric ratios from the balanced equation to determine the exponents in the equilibrium expression. In this case, the stoichiometric coefficients are already 2, 3, 2, and 2.
Therefore, the correct form of the equilibrium expression for this reaction is:
Kc = ([PbO]^2 × [SO2]^2) / ([PbS]^2 × [O2]^3)
In this specific case, Kc is equal to SO2^2 / O2^3 because the stoichiometric coefficients of PbO and PbS happen to be the same (2) and therefore cancel each other out in the equilibrium expression. So the expression simplifies to ([SO2]^2) / ([O2]^3).
Remember, this is just one example of how to derive the equilibrium expression for a given reaction. The key is to balance the equation correctly and use the stoichiometric coefficients as exponents in the equilibrium expression.
The correct form of the equilibrium expression for the given reaction is:
Kc = [SO2]^2 / [O2]^3
This arrangement of the equilibrium expression is determined by the stoichiometric coefficients of the reactants and products in the balanced chemical equation. The coefficients indicate the molar ratios between the reactants and products in the reaction.
In this case, the stoichiometric coefficients tell us that it takes 2 moles of SO2 to produce 3 moles of O2. Therefore, the concentration of SO2 is squared in the equilibrium expression, while the concentration of O2 is cubed. This is because the equilibrium constant (Kc) is defined as the ratio of the concentration of products to reactants, with each concentration term raised to the power of its coefficient in the balanced equation.
Hence, in this reaction, the equilibrium expression is written as Kc = [SO2]^2 / [O2]^3.
Your way of wording the question is confusing. IF YOU MEAN,
2PbS(s) + 3O2(g) <== 2PbO(s) + 2SO2(g)
then Keq = produces/reactants and the equation is reversed from the usual direction.
So Keq = (O2)^3/(SO2)^2
The "reverse arrow" part is the confusing part. Write the arrow the way the reaction is given instead of using words.